President Franklin Delano Roosevelt famously declared at his first inaugural address that “the only thing we have to fear is fear itself.”

The idea that economic pessimism could be a self-fulfilling prophecy is once again gaining currency because of the contrast between strong data about the economy and widespread fears that a recession could be looming.

The most recent survey of the American public by CNBC provides an excellent illustration. Average holiday spending plans rose above $1,100, a jump from around $900 a year ago and the first time the holiday survey has seen an average number above $1,000. That’s an indication that many Americans are feeling flush right now, which likely reflects very low unemployment, low levels of layoffs, and real wage growth.

But American views of the broader economy do not reflect that optimism. The share of Americans who say they are optimistic about the economy now and in the future fell 9 points to 39 percent, the steepest decline in the 12 year history of the survey. The share who are pessimistic soared 5 points to 35 percent.

The share of Americans viewing the economy as excellent or good dropped 8 points to 50 percent. That’s still above average for the report, which indicates that it is the outlook for the future that that has driven the decline in overall optimism. Which is what the data show: the share of American believing the economy will improve dropped 5 points to 31 percent, bringing it back down to the financial crisis scarred long-run average.

“The decline wiped out a big part of the gain that ensued after President Donald Trump took office,” CNBC’s Steve Liesman reported.

A Duke University survey of chief financial officers released Wednesday had even more shocking results. More than 80 percent of CFOs are forecasting a recession between now and the end of 2020. That extreme level of pessimism may be an economic drag, the Wall Street Journal‘s Greg Ip explained recently.

As John Maynard Keynes long ago noted, businesses are often driven by animal spirits, not hard cold analysis. So when a survey by Duke University finds almost half of U.S. chief financial officers believe a recession will strike the U.S. economy by the end of 2019, it’s worth wondering whether they will act on that belief, for example by curbing investment and hiring, and thus make such an outcome more likely.

What’s driving the rise in economic pessimism? There are plenty of candidates.

Tariff Fear-Mongering. Despite data showing that U.S. tariffs have not weighed on domestic manufacturing, have not cost jobs for American workers, and have not pushed up consumer prices, media outlets continue to publish stories claiming that treat the forecasts of critics of the tariffs as if they have actually occurred. So even though tariffs are not hurting the U.S. economy, Americans may believe they are.

Free Trade Fundamentalism. The corporate leaders of America came up through the ranks at a time of falling U.S. trade barriers and rising globalization. This means that many executives are believers in the system in which they have thrived. Chief financial officers, especially, may be prone to bias against tariffs and the Trump administration’s trade policies.

Volatile Stock Markets. Tbe stock market has had a much more volatile year in 2018 than it did in 2017. The major indexes are now flat to slightly-positive for the year, with some of one-time stalwarts of corporate America, like General Electric, suffering horrific downturns.

Sluggish Housing Market. Many Americans have most of their wealth and savings in their home equity. Home sales have slowed, as has home price appreciation. And since the last recession and financial crisis was wrapped around the housing market crash, Americans may be particularly sensitive to any signs of trouble in this area.

Fears of a Fed Mistake. The Federal Reserve says it wants to extend the economic expansion but its latest projections, from its September meeting, showed that its policymakers were forecasting a hike at their December meeting and three more hikes next year. Many investors now view that as unrealistic and some fear that if the Fed sticks to its plan, it could accidentally push the economy into a recession.

Democrats Took the House.The election of Donald Trump led to a surge in optimism. The midterm elections, in which the Democratic Party won control of the House of Representatives, has been followed by flagging optimism. That could indicate that Americans fear the Trump agenda could be stymied or that Democratic policies could hurt growth.

Rising Anti-Growth Socialists. The midterms also saw the rise of politicians who are far to the left of Obsma-era Democrats, with some explicitly describing themselves as socialists. They have already announced a number of anti-economic growth positions. Amazon’s plans to expand in Queens, New York, for example, are meeting with leftwing resistance.

#Resist. The left in America is far more pessimistic about the economic future than the right. In fact, most of the decline in optimism detected by the most recent CNBC survey came from Democrats and independents. That’s consistent with many other surveys of consumer sentiment. So rising pessimism could just reflect an increasingly intense opposition to Donald Trump’s presidency.

Storms and Fires. Over the past few months, the American south has been hit by hurricanes while California was ravaged by wildfires. These natural disasters destroy wealth, although they can lead to increased economic activity as people rebuild what they lost.

Expansion Senility. Economic expansions do not typically die of old age. When the economy falls into a recession, it is usually because a financial bubble has burst, fiscal policy has gone awry, or monetary policy tightens to combat inflation. But as we do not have very many expansions that have lasted as long as this one, so history may not be a good guide. Perhaps expansions can die because people go a bit crazy and become convinced that the good times must be ending simply because they have gone on too long.

Whatever its source, economic fear is on the rise. And that may be reason to worry.